I had this recurring thing where Irfanview would get stuck on the last file type I saved an image as. E.g. if I chose to save as .ico (just for that one time around, Irfanview would keep remembering that. I suppose that’s handy for some things, but I want .jpg as the default, w/o me having to change it manually each time.

I found a couple of items, one or both of which might be enough, that is if you’re having the same problem. Look for i_view32.ini on your system, then look for this section:

[Save]
ViewMode=28751
SaveDir=C:\Users\username\My Pictures
SaveExtension=jpg

^^ The last line is the one I had to change.

Also there’s this line, in the same ini file:

SaveIndex=8

8 denotes .jpg, so that’s that.

I’d point to the source link, but Firefox thinks it’s now unsafe, and IE won’t show anything but an Irfanview icon. Something’s up there, don’t know what.

Hope it helps.